Yoga reminds me obscurely of when I was in college and taking Physics 101 and Calculus 101 at the same time. Physics, as you may know, uses a lot of calculus and I often found that I would encounter a calculus concept in physics class first. Because the physics gave me some real-world application for the math concept, and also because my physics prof was a much better teacher, I got a much better understanding of calculus from taking the two classes together than I would have from taking Calc 101 alone.
Yoga has the same kind of relationship with the stuff I've been doing with a series of trainers at the gym for... gosh, over ten years now. Both are concerned with strength, balance, stability, and especially core strength. Both spend a lot of time on proper posture and doing the moves in a way that won't put undue strain on muscles, joints, or ligaments. But the yoga instructors (all the instructors at this studio are also physical therapists) give me a lot more of the theory, such as explaining why my tight hamstrings make my feet turn out. At the same time, my gym workouts give me practical applications for the yoga concepts.
I find that the time I've spent at the gym makes the yoga exercises easier, while my yoga classes make my gym workouts make more sense. It's all one body.